The apparatuses for the tensioning of warp threads have a tensioner beam which is under spring action and/or is in contact with electric motors in order to maintain the tension of the warp threads. In this the introduction of the force takes place at both ends of the tensioner beam.
Normally, quite big load acts on the tensioner element (7) in particular at large web widths as in a loom and when a heavy fabric is woven. It is disclosed, for example in EP 0 271 021 or EP 0 396 501, to introduce the force into the tensioner element (7) at one side of the element (7). This causes torsion of the tensioner element (7) with respect to the longitudinal extent of the element (7). Therefore, tension of the warp threads is different in longitudinal direction, which causes an irregular fabric. In particular technical fabrics, for example used for filters or air bags, must be very regular and therefore cannot be produced by the apparatus disclosed in EP 0 271 021 or EP 0 396 501. Alternately, the tensioner element (7) can be made massive.
It proves disadvantageous that the tensioner beam must be made massive in order to avoid a torsion, in particular at large web widths. A tensioner beam with a large mass already represents a disadvantage per se.